Secure Digital Memory Card is a kind of semiconductor flash-based memory card developed by Toshiba and SanDisk. According to storage capacity, SD cards are divided into several types including SD, SDHC and SDXC. And different types of SD cards are employed in different devices. Is SD card as secure as expected? Here, we'd like to introduce some news about SD card. Just as a piece of news goes that some powerful and handy microcontrollers that are useful to hackers are contained in SD cards. Certain microcontrollers can be used to oversee the details of data storage. Once those controllers are used by malicious users, SD card data security is woefully insecure. Is it the case? Well then, several possible factors which may pose menace to SD card data security are introduced.
As mentioned above, the existence of microcontroller may make SD card data security insecure. However, beside microcontroller, other items such as flash memory and SD card firmware will cause the same effect.
Flash memory affects SD card data security
In order to minimize cost and maximize storage space, engineers have to continue the never-ending fight with internal entropy, which slowly but surely scrambles the data on every flash drive. Since flash memory is made at extremely low price, flash memory will unavoidably be riddled with defects such as data security issues. Moreover, there exists certain illusion of contiguous and reliable storage media with the development of data storage technology. Therefore, engineers are trying to make flash memory cheaper and cheaper, and attain the illusion at the same time. However the reliability of flash memory gets lower and data security can not be guaranteed, for it is hard to strike a balance between theory and reality. To achieve certain goal, engineers come up with more intricate algorithms in SD cards.
Data security threats brought by SD card firmware
Firmware, which can change the visible available space on certain card without altering the actual available space, is contained in SD card. To let users have a better understanding of possible data security threats brought by SD card firmware, we'd like to give an example. Unknowing the special ability possessed by SD card firmware, some users are most likely to sell a 2GB card as a 4GB card. Furthermore, users will find it hard to notice certain difference until the fake space is filled up. Users can attribute the brought consequences to certain SD card firmware. Providing that data stored in certain space are of great significance, users are most likely to suffer from massive losses. Owing to the very facts, SD card users are supposed to destroy the discarded SD card to protect SD card data security.